1. Acid/Base Chemistry

2. Strong Acids & Bases Dissociate completely in water
Also known as strong electrolytes
Electrolytes conduct electricity in aqueous solutions
The more ions dissociated…the more electricity conducted

3. Properties of Acids & Bases
Produce H+ ions when dissolved in water (H3O+ = hydronium )
Produce OH- ions when dissolved in water

4. Properties of Acids & Bases
Taste tart or sour
Taste Bitter

5. Properties of Acids & Bases
Feel Slippery
Corrosive to body tissue

6. Properties of Acids & Bases
Turn blue litmus red
Turn red litmus blue

7. Properties of Acids & Bases
Electrolytes

8. Arrhenius Acids & Bases
Arrhenius proposed that in an aqueous solution a strong electrolyte exists only in the form of ions, whereas a weak electrolyte exists in part as ions and partly as molecules

9. Arrhenius Acids & Bases
Arrhenius Base – gives off OH-1 in aqueous solution
Example:
KOH --- K+1 + OH-1
H2O

10. Arrhenius Acids & Bases
Arrhenius Acid - gives off H+1 in aqueous solution
Example:
HNO3 -- H+1 + NO3-1
H2O

11. Strong acid + Strong Base
Example:
HCl(aq) + NaOH(aq)  NaCl(aq) + H2O(l)
Products = water and a salt

12. Flaw in Theory
This theory suggests that all bases have OH-
This does not explain how substances like NH3 are bases

13. Bronsted-Lowry Acids & Bases
Another definition of what an acid and base are
Bronsted Acid – Proton (H+1) donor
Bronsted Base – Proton (H+1) acceptor

14. NH3 + H2O NH4+ + OH-
Base
Acid
In the reverse reaction, the OH – would be the base and the NH4 would be the acid

15. Bronsted-Lowry Acids & Bases
Example:
HCl + NH3  NH4+1 + Cl-1
Which is the acid and which is the base?
ACID
BASE

16. Conjugate Acids & Bases
Conjugate Base – what remains after a Bronsted-Lowry acid has given up a proton (AN ACID HAS A CONJUGATE BASE)

17. Conjugate Acids & Bases
Conjugate Acid – what remains after a Bronsted-Lowry base has accepted a proton (A BASE HAS A CONJUGATE ACID)

18. Conjugate Acids & Bases
Let’s Look at a few examples:
HCl NH NH Cl-1
Conjugate
Base
Base
Conjugate
Acid
Acid

19. Conjugate Acids & Bases
H2SO4 + H2O  H3O+1 + HSO4-1
Acid
Base
Conjugate
Acid
Conjugate
Base

20. Conjugate Acids & Bases
HF + H2O  F-1 + H3O+1
Acid
Base
Conjugate
Base
Conjugate
Acid

21. Amphoteric Substances that can be an acid or a base
They can gain or lose H+1
H2O

22. Try This:
Of the following one is acidic, one is basic and one is amphoteric
HNO2
PO4-3
HCO3-1

23. Self-Ionization of Water
2 H2O ↔H OH-
This is constantly happening in pure water.
Equilibrium concentration expression for water: Kw = [H3O+] [OH-]

24. Self-Ionization of Water @ 25 C
2 H2O ↔H30+ + OH-
n/a [1x10-7] [1x10-7]
Ion product of Water :
Kw = [ products] = 1x 10-14
[reactants]

25. pH
Low pH = very acidic
High pH = very basic (alkaline)
7 = Neutral

26. Calculating pH pH = -log [H30 +1 ] To calculate, use:
[H30 +1 ] = hydronium
ion concentration

27. Find the pH of a solution whose [H30 +1 ] is 4.0 x 10-6 M.

28. Find the pH of a solution whose hydronium concentration is
1.0x 10-8 M.

29. What is the [H30 +1 ] of a solution with a pH of 3.2?

30. What is the [H30 +1 ] of a solution with a pH of 11?

31. So what would be the pH of water?
If the [H3O+] =
1 X ???

32. Find the pOH of a solution whose [OH-1] is 2.1 x 10-8 M.

33. What is the [OH-1] of a solution with a pOH of 9.1?

34. What is the pH if the pOH is 12.2?

35. What is the pOH if the [H30 +1 ] is 6.2 x 10-1?

36. Titrate Strong Acid with a Strong Base
What is the pH at each of the following points in the titration of mL of M HCl with M NaOH?
a) Before addition of any NaOH (initial pH)
b) After addition of mL M NaOH
c) After the addition of mL M NaOH
d) After the addition of mL M NaOH

37. Review Links